Current production tractors have an armrest which includes a plurality control devices, such as levers switches and knobs which are used to control various functions on or coupled to the tractor. It is known to couple a joystick control unit to such a command arm for controlling functions of a loader. In a current production tractor, a joystick control unit is mounted to the front of the command arm by several screws. The process to install the joystick is quite time consuming because the command arm needs to be disassembled, holes drilled, and then components reassembled. The disassembly creates the opportunity for parts to be damaged and or misplaced. Because of the difficulty in assembly of the joystick control to the command arm, the joystick control stays attached all the time, regardless if a loader is being used or not. This can become a nuisance for the operator and block some visibility over the front of the command arm. It is desired to have a command arm interface assembly which simplifies the coupling and uncoupling of a joystick and other components to the command arm.
The joystick control is also not positioned in an ergonomic friendly position. For most operators, their elbow is positioned over a hole or other switches on the command arm top, when they are operating the joystick control. This does not provide support for the elbow and becomes fatiguing after a short period of use.